Wireless networks have become commonplace. For example, many people use a wireless access point within their home to provide an internet connection to multiple TCP/IP enabled devices. Similarly, wireless networks are used in enterprise environments to provide connectivity for a variety of computing devices. A wireless access point typically operates using a version of the IEEE 802.11 wireless local area network standards (i.e., currently, the 802.11a, b, g or n standards), and desktop PCs, laptop PCs, mobile telephones, telephones, tablet PCs, net-books, video game consoles, among other devices, can connect to a wireless network operating according to these standards.
As these networking environments have grown, both in size and complexity, it is not uncommon for a wireless network infrastructure to include multiple access points. Doing so may extend both the range and capacity of a wireless network. For example, within an enterprise, multiple access points may be used to create a single, logical network. In such an environment, when a user roams outside the range of one access point, another access point takes over.
To join a wireless network, a host station first needs to authenticate itself to the network. For example, a wireless network may comply with established security standards such as WPA (Wi-fi Protected Access) or its predecessor WEP (wired equivalent privacy). In such cases, a device may authenticate itself to the wireless network by providing a password or key along with a service set identifier (SSID). In an environment with multiple access points, the SSID (and associated passwords) may be shared across the access points. Typically, a user (e.g., a network administrator in an enterprise environment) configures the network access points to share the SSID and sets the access password or key. The wireless network can also be configured to restrict access on a host-by-host basis, e.g., by specifying the MAC addresses of authorized hosts, as well as restrict access in terms of times-of-day, applications, or ports.